Feed mechanism for type-writers.



H. ETHERIDGE. FEED MECHANISM FOR TYPE WRITERS. APPLICATION FILED MAY 23,1914.

1,1 1 8,406. Patented Nov. 24, 1914.

2 SHBIITBSHEET 1.

Wzlwsses.

H. ETHERIDGE. FEED MECHANISM FOR TYPE WRITERS.

APPLICATION IILED MAY 23, 1914.

Patented Nov. 24, 1914.

2 SHEETS-SHBET 2.

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HERBERT ETHERIDGE, 0F WIMBLEDON PARK, ENGLAND, ASSIGNOR TO THE BABI'LOCRTYPEWBITER COMPANY LIMITED, OF LONDON, ENGLAND.

FEED MECHANISM FOR TYPE-WRITERS.

Specification of Letters Patent.

Patented Nov. 24, 1914.

Application filed May 23, 1914. Serial No. 840,475.

To all whom it may concern:

Be it known that I, HERBERT Ernaaroen, a subject of the King of England,residing at Wimbledon Park, in the county of Surrey, England, haveinvented certain new and useful Improvements in Feed Mechanism forType-Writers, of which the following is a specification.

This invention relates to the feed mechanism for the platen carriages oftypewriters and has for its object to provide an improved form of suchmechanism.

he present invention consists in the combination in a typewriterescapement mecha nism of an escape-wheel, a pivoted pawl and ratchet,-one of which members moves with the escape-wheel, and the' other withthe feed pinion for the carriage, and means for swinging the pawl aboutits plvots to disengage it from the ratchet at will to free theescape-wheel, said means being so disposed as not to interfere with thep votal movement of the pawl when permitting backward movement of thecarriage. i

The escapement wheel may be carrledon a spindle having a pinion thereonwhleh meshes with the platen-carriage rack of the typewriter, theescapement wheel being free to rotate on the spindle and opcratively connected with the spindle by the ratchet and pawl, a back-spacing pinionbeing also mounted on the spindle and provided with a key-operated pawlfor actuating the backspacing pinion.

The ratchet and pawl connection between the spindle and the escapementwheel malty tie comprise a ratchet wheel mounted on escapement wheel,project laterally from the wheel parallel with the axis of the spindle,a U-shaped pawl-member pivoted transversely on the spindle and having asegmental series of teeth at the base of the U to engage the ratchetwheel on one side of the pivot and means engaging the free ends of the Uon the other side of the pivot for operating the pawl.

The pawl may be actuated by a plate surrounding the escapement wheelspindle and. adapted by movement axially of the spindle to engage thefree arms of the pawl to operate it; this plate may be operatedindependently by the tabulator key or keys and by the carriage releaselever.

In the accompanying drawings Figui-e whereof the ratchet teeth- 1 is aview of the escapement mechanism from the rear of the machine; Fig. 2 isa plan in section on the line 2-2 of Fig. 1. and Fig. 3 is a perspectiveview of a detail:

Like reference letters indicate like parts throughout the drawings.

The spindle A is mounted in bearings A, A n the frame of the machine andcarries at its upper end a pinion B meshing with the rack on the platencarriage. An escapement wheel C is carried on a sleeve C loose on thespindle A and on the upper side of the wheel C is a crown ratchet wheelC whose teeth C" extend in a direction parallel with the axis of thespindle A. A pawl member D is mounted on a pivot D transversely disposedon the spindle A. The pawlmember D is of U-shape and it is pivoted aboutthe middle of the length of each arm of the U. The bottom of the U isprovided with a series of teeth D shaped to conform to the ratchet teethC on the wheel C and a spring D mounted on the pivot pin D is arrangedto hold the teeth D, C normally in engagement.

The lower end of the spindle A has mounted fast on it a back-spacingpinion E and a pawl E is provided to operate this pinion and feed itback in steps of one tooth each. This pawl is operated by the link andlever connections E E, E, Fig. 2, from a key conveniently situated onthe front of the machine. It will be understood that the pawl E isarranged to feed the pinion E in the reverse direction to that in whichitnormally travels under the control of the letter-spacing mechanism.

The means for releasing the pawl-member D from engagement with theratchet wheel 0 comprises a plate F surrounding the spindle and carriedon two arms F suitably guided in the framework of the machine. lhe plateis normally held up out of engagement with the pawl-member by the springF Above the ends of the arms F there is disposed on the platen carriagea. rod G which is capable of being depressed by the carriage-releaselever G. A springcontrolled detent C enga es the escapement wheel C andprevents it rom being turned backward.

The tabulator keys, of which there are provided a number correspondingwith the number of tabulator stops on the platen carriage, are eachconnected to levers H which are arranged to bear on the upper side ofthe plate l and depress it when a tabulator key is depressed.

It will be appreciated that the hereinbefore described construction ofpawl-member D and its operating plate F is such that although thepawl-member is carried around with the spindle it can be engaged andoperated in any position in its rotation by the plate F; also that theprovision of a segmental series of teeth D on the pawl 1nstead of only asingle tooth diminishes the wear and increases the reliability of. themechanism.

The operation of the mechanism is as follows :The platen carriage is fedalong in the ordinary manner by a spring under the control of theescapement wheel C. The rack on the platen carriage engages with thepinion B on the spindle, thereby causing it to rotate and carry with itthe pawl-member D which normally engages the ratchet teeth C and''carries the escapement-wheel around with it. The movement oif theescapement-wheel is'controlled by dogs K operated by the key-levers orspace-bar. When it is required to return the platen carriage to beginanother line, it is pushed back and the teeth D of the pawl rideover theteeth U of the ratchet wheel, so that this return motion is permittedand the escapeinentwheel C remains stationary. .lf it is required to setthe platen carriage back by one or two spaces the back-spacing key isdepressed and the pawl'll is thereby brought into engagement with thepinion E causing it to turn the spindle back by the required amount. Thepinion D is fast on thespindle and by its engagement with the platencarriage rack it moves the platen carriage back the required amount.During this movement the teeth D of the pawl again ride over the teeth Cof the ratchet wheel C The spring-controlled detent C prevents backwardrotation of the escapement-wheel C. This is provided because thefriction of the pawl riding backward over the ratchet-teeth. may besuflicient to carry the escapement-wheel back until its teeth engagewith the other side of the dog which is holding it. JVhen this occursthe pawl teeth D would not engage in the correct position with theratchet-teeth C and the platen carriage, which has been moved back, willmove forward again to take up this movement of the escapement wheel.

When the tabulator mechanism is operated the teeth ID on the pawl arelifted out of engagement with the teeth G and the carriage is free totravel under the actionof its 'driving spring until'the tabulator stopscome into engagement. During this movement the spindle rotates freely,as the pawl is held out of engagement, owing to the plate F engaging thearms D all'times during their rotation. A similar action occurs when thecarriage-realease lever G is operated. The pawl is held out ofengagement and the carriage is free to travel through any requireddistance.

It will be understood that throughout this specification where the termtypewriter is used any typing mechanism, such for example as issometimesemp'loyed in an adding machine, is intended to be included.

What I claim as my invention and desire to secure by Letters Patentis 1. In a typewriter-escapement-mechanism the combination of, aspindle, a carriagefeed-pinion thereon, an escapement-Wheel thereon, oneof the elements on the spindle being fast with the spindle, aratchet-andpawl operatively connecting the pinion and the wheel, andmeans for swinging the pawl about its pivotal axis to disengage it fromthe ratchet at will, said means not interfering with the free pivotalmovement of the pawl when riding over the ratchet, substantially as setforth.

2. In a typewriter-escapement-mechanism the combination of a spindle, acarriage- :teed-pinion fast thereon; an escapementwheel loose thereonand having in" addition to the escape teeth a set of ratchet teeth, apawl carried around with said spindle and pivotally mounted. thereon tocooperate I with said ratchet-teeth in such manner as to operativelyengage it with the spindle, means engaging said pawl and movable toswing it pivotally out from engagement with 'the ratchet-teeth, saidmeans not interfering with. the free pivotal movement of the pawl whenriding over the ratchet, substantially as set forth.

3. In a typewriter-escapementmechanisin the combination of a spindle, acarriagefeed-pinion fast thereon, an escapement wheel loose thereon, andhaving inaddition to the escape-teeth a series of ratchet-teethprojecting parallel with the axis of said spindle, a U-shapedpawl-member pivoted transversely on said spindle and having on one sideof the pivot a segmental series of teeth at the base of the U to engagethe ratchet-teeth and means engaging the free ends of the U-shaped pawlon the other side of the pivot and movable to disengage it from theratchet-teeth at will, said means not interfering with the free pivotalmovement of the pawl when riding over the ratchet, substantially as setforth.

4. Tn atypewriter-escapement-mechanisrn the combination of a spindle, acarriagefeed-pinion fast thereon, an escapementwheel loose thereon,having in addition to the escape-teeth a series of ratchet-teeth, a pawlrotating with said spindle and pivoted thereon, cotiperatingwith saidratchet-teeth, a plate surrounding said spindle and movable axiallythereof to engage the free end its v of the pawl and swing it out ofengagement with said ratchet, substantially as set forth.

5. In a typewriter the combination of a spindle, a carriage-feed-pinionthereon, an escapement-Wheel thereon, a ratchet-andpawl operativelyconnecting the wheel and pinion, means for swinging the pawl about itspivotal axis to disengage it from the ratchet, a carriage-release leveroperatively 10 connected to said means, and tabnlator-keys alsooperatively connected to said. means, substantially as set forth.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

HERBERT ETHERIDGE.

Witnesses:

HARRY B. BRIDGE,

A. J. Cowmc.

